The proper illumination of a subject being photographed is most important in the production of high quality photography, and photographers utilize a wide variety of lighting devices in achieving the desired illumination. Artificial illumination includes direct lighting, indirect lighting, and a variety of light reflectors, flash units, windows, and other light sources are employed to achieve the desired result. Usually, the light source is stationary with respect to the subject being photographed and the camera during exposure of the film, and the intensity of the illumination, the distance of the illuminating devices from the subject, the reflective quality of the subject, the aperture or diaphragm setting of the camera, and the lens to be used, all affect the illumination characteristics with respect to the end result achieved, and photographers often go to great lengths to achieve the desired lighting effect.
As the source of illumination during photography is normally fixed, shadows may result when photographing three dimensional subjects, and a variety of techniques are utilized to eliminate or control shadows to enhance the photograph, or emphasize the shape and configuration of the subject.
A plurality of lamps are usually required to uniformly illuminate subject matter of complex form. For instance, when photographing a relatively large machine tool, automobile, or other item of complex configuration a great number of lamps are utilized to control shadows and produce the desired effect. Considerable time and expense is involved in setting up the lighting equipment when photographing complex three-dimensional subjects, and even with care it is often difficult to control the illumination intensity and location to the extend desired.
It is known to employ a moving light source when photographing a stationary subject, and a shielded light held in the hand of the photographer has been employed to illuminate the subject while in the dark wherein the photographer using a painting motion washes the light upon the subject while the camera aperture is open to minimize uneven illumination, and such illumination practices have been known as "painting with light". However, as the movement and support of the shielded light is manual it is not possible to produce even illumination upon the subject, and if the subject has a light reflective surface the light will be reflected therefrom causing white streaks across the photograph rendering the photograph unacceptable for most purposes.
When photographing subjects having light reflective surfaces the reflection from such surfaces of the illumination lamps is always a problem, and it is usually necessary to use diffused or indirect light to avoid undesirable highlighting, although highlighting is often desirable to emphasize the configuration and appearance of the subject.
It is known to support photographic illumination lamps for adjustable purposes, such as shown in U.S. Pat. No. 3,378,678, and it is also known to modify and enhance photographic negatives at predetermined locations due to over or underexposure by employing "dodging" techniques such as shown in U.S. Pat. Nos. 2,860,561 and 3,158,478. However, in the prior art methods and apparatus have not been disclosed which achieve the results of the invention due to the controlled movement of a uniform light source, and in the practice of the invention results are achieved not heretofore suggested or taught by others.
It is an object of the invention to provide a method for illuminating a subject to be photographed wherein a uniform highlighting of subject matter having a reflective surface is possible.
Another object of the invention is to provide a method for illuminating a subject being photographed wherein a substantially uniform illumination of the subject throughout the exposed subject surfaces can be achieved with a single light source and shadows and underexposed areas substantially illuminated.
Another object of the invention is to provide a method for illuminating subject matter to be photographed wherein the subject background may be modified in its contrast to the subject, and if desired, the background may be completely obliterated from the photograph.
Another object of the invention is to provide apparatus for illuminating a subject to be photographed wherein an illuminating source is mounted for displacement at a predetermined rate relative to the subject whereby various surfaces of the subject will be illuminated from various directions during the photographing procedure.
Yet another object of the invention is to provide apparatus for illuminating the subject to be photographed utilizing a light source emitting a uniform intensity of light through a vertical dimension greater than the vertical dimension of the subject being photographed wherein a uniform highlighting of the subject is achieved.
An additional object of the invention is to provide illumination apparatus for illuminating a subject being photographed wherein a uniform light source of a vertical dimension greater than the subject matter being photographed is mounted upon a portable support capable of translating the light source at a predetermined and uniform rate of movement relative to the subject.
In the practice of the invention a uniform source of light which has a vertical dimension greater than the vertical dimension of the subject being photographed is mounted for movement at a predetermined uniform rate relative to the subject. The source of illumination comprises an elongated light source, such as a reflector or tube of light, such as a fluorescent tube, and although the light source is relatively narrow in its horizontal dimension its height is usually several feet, and in some instances in excess of fifteen feet.
In one embodiment, the light source is suspended from a ceiling-mounted, motor-driven support wherein the light source is capable of rotating in a complete circle about the subject being photographed. During photographing, the aperture of the lens remains open at a predetermined exposure opening, and the light source is passed across the subject between the subject and camera while being shielded from the camera. The light source is translated at a uniform predetermined rate, and as the light source is moved the subject is uniformly illuminated across those surfaces disposed toward the camera, and shadows and underexposed areas on the subject are substantially reduced. By correlating the aperture opening with the intensity of the light and the rate of movement of the light source, a photograph of superior quality is produced.
As the light source has a vertical dimension greater than the vertical dimension of the subject being photographed, and as the light source is uniformly moving during film exposure, a highlight on the subject is produced throughout the height and width of the subject. If the subject contains light reflective surfaces and if objectionable overexposure occurs at a few locations, the aperture of the lens can be reduced while the light passes those locations.
If it is desired to modify the background behind the subject, the light source is displaced behind the subject at its uniform rate of movement, and as the vertical dimension of the light source is greater than that of the subject, and as the light source travels the entire horizontal field of the film image, the film will be exposed to the light directly emitting from the light source as it travels across the background. This direct exposure of the light source to the film negative exposes the film negative except for that portion directly behind the subject. Accordingly, a "wall of light" is disposed behind the subject during photographing and the contrast of the background with respect to the subject may be closely controlled. For instance, the background may only be "washed" so that the background only appears in a light form, or, it is possible to completely obliterate the background wherein the background appears as a white wall and a sharp delineation exists between the white background and the edges of the subject
In another embodiment of the invention the light source is mounted upon a portable carrier in the form of a small cart which is driven by an electric motor at a uniform rate of movement. The cart supports batteries which, in addition to driving the cart, energize the elongated illumination source which mounts upon the cart and extends thereabove. The cart is steerable, and, if desired, could be steered by remote control upon remote control apparatus being drivingly associated with the steering wheel.
The portable illumination apparatus is used when photographing large subjects, such as machine tools, vehicles, or the like, and the vertical height of the light source is greater than the height of the subject being photographed. As the light source as mounted upon the cart is capable of circumscribing the subject, the subject will be illuminated on the sides exposed to the camera, and as the light source and cart pass across the rear of the subject the background can be modified as desired, and in many cases entirely obliterated to produce a white background. Thus, when photographing the subject in a factory or the like wherein the background is objectionable, the use of the invention permits the background to be completely masked out merely by passing the light source behind the subject. With conventional methods of photography, a white backdrop would have to be disposed behind the subject to produce a comparable effect, and the installation of such a backdrop, or retouching of the photography would be required, and in the use of the invention substantial cost savings are experienced.